The present invention relates to ignition systems for internal combustion engines. More specifically, the invention relates to an ignition system of the inductive type having certain novel features.
Inductive ignition systems are well-known in the art. Conventionally, such systems use a primary coil and a secondary or ignition coil. The primary coil is connected such that a current can flow through it. At a predetermined point in the piston's stroke, a transistor in series with the primary coil circuit opens. As a result, the current through the primary coil quickly goes to zero.
This rapid change in current through the primary coil induces a voltage across the secondary coil sufficient to arc across a spark plug gap on a spark plug attached to the secondary coil circuit. The number of windings in the primary and secondary coils is such that the voltage induced in the secondary coil is high enough to arc across the spark plug gap.
An example of a conventional inductive ignition system is disclosed in U.S. Pat. No. 4,487,191, the disclosure of which is incorporated herein by reference.
While conventional inductive ignition systems have been successful at firing a spark plug at approximately the same time during successive rotations of a piston-cylinder engine, there is a need for more precise control over the exact time of firing and the duration/intensity of the spark. Such a new ignition system would have the further benefit of reducing emissions and reducing wear on the engine due to combustion at a non-ideal time in the engine cycle.